Best iPad 2 app for student file? Data? Forms? Etc

Hello, my name is Joe. First post here and I am a third grade teacher looking to expand the use of my iOS devices in my classroom this year. I am trying to find a good app that would allow me to create a "file" for my students that would be easy to access in one place, be versatile and also able to be modified.
This would have student names, collections of assessment data (tests, pictures of authentic work, archival records, etc) as well as I planned to scan, add and modify/annotate over PDFs in this "database" flie of sorts.

I have looked at TapForms and Bento for starters...can anyone else suggest something that is good or recommend either one of these products? The idea is that once setup it would be easy to maintain, etc. Having everything in one place so that you don't have to use multiple programs.
Is there a app that allows you to create such "tabbed" files and also allows for PDF annotation, audio, video , etc?